TW: possible miscarriage

I am 12 weeks pregnant and yesterday I started having very light pink bleeding and today it’s brown, throughout the day it has gotten slightly heavier and I have started having cramps. I also have an urge to pee too, not sure if that’s just from the cramps. I called doctors office and they didn’t call back and are now closed. Do I hopefully just have some kind of UTI? Also two days ago I started having pretty bad nausea and have thrown up a couple of times, I have not gotten sick yet during this pregnancy.